Automated buffer setting

ABSTRACT

Method, system, and computer program product for assigning various operations to itineraries that can be assigned to personnel. Past instances of an operation are analyzed to determine at least one time variance associated with a reliability factor. A combination of operations, with the respective at least one predicted time variance, that does not exceed at least one personal limit of personnel can be identified. The identified combination can be assigned to an itinerary.

FIELD

Aspects described herein relate to personnel scheduling, and morespecifically, to preparing schedules of tasks for personnel based on alikelihood that the schedules of tasks will not exceed a personal limitof a person assigned to the itinerary and/or based on priority rankingsfor the tasks.

SUMMARY

According to one aspect, a method for assigning personnel to variousoperations includes selecting a reliability factor. The method furtherincludes determining at least one predicted time variance for thevarious operations based on past instances of the various operations andthe reliability factor. The method further includes identifying apossible combination of operations, including the respective at leastone predicted time variances, that does not exceed at least one personallimit of the personnel. The method further includes assigning theidentified combination of operations to an itinerary.

According to one aspect, a system can include memory storing pastinstances of various operations. The system can also include a processorconfigured to receive a reliability factor. The processor can also beconfigured to determine at least one predicted time variance for thevarious operations based on past instances of the various operations andthe reliability factor. The processor can also be configured to identifya possible combination of operations, including the respective at leastone predicted time variances, that does not exceed at least one personallimit of the personnel. The processor can also be configured to assignthe identified combination of operations to an itinerary.

According to one aspect, a computer program product for assigningpersonnel to various operations can include a computer-readable storagemedium having computer-readable program code embodied therewith. Thecomputer-readable program code can be executable by one or more computerprocessors to receive a threshold reliability factor. Thecomputer-readable program code can also be executable by one or morecomputer processors to determine at least one predicted time variancefor the various operations based on past instances of the variousoperations and the reliability factor. The computer-readable programcode can also be executable by one or more computer processors toidentify a possible combination of operations, including the respectiveat least one predicted time variances, that does not exceed at least onepersonal limit of the personnel. The computer-readable program code canalso be executable by one or more computer processors to analyze pastinstances of the operation to assign the identified combination ofoperations to an itinerary.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a block diagram illustrating an exemplary duty schedule for apilot over a two-day period;

FIG. 1B is a block diagram illustrating an exemplary duty period for apilot in which the pilot is scheduled to perform four flight segmentsduring the duty period;

FIG. 1C is a block diagram illustrating an exemplary duty period for apilot in which the pilot is scheduled to perform four flight segments,but the fourth flight segment would exceed the pilot's duty period;

FIG. 2A is an exemplary data table for past instances of a flightsegment illustrating a method for determining reliability factors foroperating time variances, wherein the operating time variance is anarrival time variance;

FIG. 2B is an exemplary data table for past instances of a flightsegment illustrating a method for determining reliability factors foroperating time variances, wherein the operating time variance is a blocktime variance;

FIG. 3 is a block diagram of a method for assigning future instances offlight segments to crew itineraries;

FIG. 4 is a block diagram illustrating flight crews of inbound flightsegments being assigned to outbound flight segments based on a “first infirst out” process;

FIG. 5A is an exemplary data table that illustrates a method forassigning a priority to different flight segments;

FIG. 5B is an exemplary table that illustrates acceptable reliabilityfactors or risk levels associated with different priorities;

FIG. 6 is a block diagram illustrating flight crews of inbound flightsegments being assigned to outbound flight segments based on a “first into highest priority” process;

FIG. 7A is block diagram of a method for assigning future instances offlight segments to combinations of flight segments based on a likelihoodthat a combination will cause a pilot assigned to the combination toexceed a personal limit and based on a priority of the flight segment;and

FIG. 7B is a block diagram of a method for assigning pilots to futureinstances of flight segments based on a priority of the flight segmentand based on pilots having the highest available personal limits.

DETAILED DESCRIPTION

In various industries, assigning personnel (e.g., employees) to tasks orjobs can be limited by personal limits for the personnel. For example,commercial airline pilots have several different personal limits relatedto the length of time they can be on duty that can limit how the pilotscan be assigned to different flight segments.

FIG. 1A illustrates a two-day timeline 102 of an exemplary duty scenario100 for a pilot of commercial aircraft. In the scenario 100, the pilothas a first duty period 104 a during a first day and a second dutyperiod 104 b during a second day. The first duty period 104 a and thesecond duty period 104 b are separated by a rest period 106. Governmentregulations (e.g., Federal Aviation Administration regulations), airlineregulations, union rules, and the like may dictate personal limits forhow long the duty periods 104 a and 104 b can be and may also dictatehow long the rest period 106 between the two duty periods 104 a and 104b needs to be.

FIG. 1B provides a more detailed view of an exemplary duty period 104for a pilot. In the exemplary duty period 104, the pilot has beenassigned to an itinerary of four flight segments 108 a, 108 b, 108 c,and 108 d (collectively, flight segments 108). Each of the flightsegments 108 defines a block time, which is an elapsed time from when anaircraft is pushed back from a gate at a departure airport to when theaircraft stops at a gate at an arrival airport. Again, governmentregulations, airline regulations, union rules, and the like can dictatepersonal limits for how much block time a pilot can accumulate during aduty period 104 and how long the pilot can be on duty.

As shown in FIG. 1B, the duty period 104 can begin at an earlier timethan the first flight segment 108 a. As an illustration, a pilot maybegin his duty period 104 when he arrives at the airport at 6:00 AM.However, the pilot's first flight segment may not depart the gate until6:45 AM. In such an instance, a time gap 110 a of forty five minutesexists between the beginning of the pilot's duty period 104 and thebeginning of the block time for the first flight segment 108 a.Similarly, the pilot may need time between flight segments to travelfrom a first aircraft to a second aircraft, review the flight plan forthe next flight segment, etc. Thus, time gaps 110 b, 110 c, and 110 dare inserted between flight segments 108 to allow for such pilottransitions. The length of the time gaps 110 b, 110 c, and 110 d thatmay be needed for pilots to transition can vary depending on theairport, time of day, time of year, etc. For example, at a large, busyairport such as O'Hare International Airport in Chicago Ill., a pilotmay need an hour or more to transition from a first aircraft afterflying a first flight segment to a second aircraft for a second flightsegment. At a smaller, less-congested airport, a pilot may only need ahalf-hour to transition from a first aircraft after flying a firstflight segment to a second aircraft for a second flight segment. Asanother example, on a weekday morning when airports are busy, a pilotmay need more time to transition from a first flight segment to a secondflight segment than may be needed on a weekend afternoon when theairport may be less crowded.

Ideally, a pilot's duty period 104 includes a time gap 110 e between theend of his last flight segment 108 d and the end of the duty period 104.Such a time gap 110 e can ensure that the pilot does not exceed histotal duty time on the last flight segment. FIG. 1C illustrates anexemplary duty period 104 for a pilot in which the last flight segment108 d is delayed in departing. As a result, if the pilot performed thefourth flight segment, he would exceed his allowable duty time. Forexample, referring again to FIG. 1C, if the fourth flight segment 108 dis delayed such that the aircraft will not arrive at the gate before thepilot's duty period 104 ends, then the pilot cannot fly the flightsegment 108 d, and a different pilot has to perform the flight segment.By contrast, if the fourth flight segment 108 d takes off on time (asshown in FIG. 1B) but is delayed in the air (e.g., by weather) such thatthe aircraft does not arrive at the gate until after the pilots dutyperiod 104 ends, such an inadvertent overage of the pilot's personallimits is permissible.

An operation can have one or more personnel time limit criteriaassociated with it. Continuing the examples above, a flight segment mayhave several personnel time limit criteria, such as personnel time limitcriteria related to block time, arrival time, and connection time. Thepersonnel time limits may be different based on a priority of anoperation. Continuing the examples above, a particular flight segmentmay have a block time of two hours and thirty minutes. A personnel timelimit criterion related to block time can be set to two hours and thirtyminutes. If the flight becomes a high priority flight segment, then thepersonnel time limit criterion related to block time may be increased tothree hours.

To avoid exceeding the personal limits of pilots, airlines can employbuffers to account for operating variances. For example, airlines mayadd an hour of extra block time to a duty period when scheduling thecrew to decrease the likelihood that the crew will actually exceed theirpersonal limits. Similarly, an airline may require a minimum connectiontime (by adding a connection time buffer between flight segments) of anhour and a half regardless of the airport, the time of day, the time ofyear, or the like. These buffers are often set to a conservative numberthat will capture most flight operations. However, a significant numberof flight operations do not require such large buffers. As a result,significant amounts of crew time can be wasted by these buffers. Forexample, if the pilot is only allowed eight hours of block time duringany given duty period 104, then an hour of block time buffer only allowsthe pilot to be scheduled to fly seven actual block hours.

For commercial airline operations, a flight segment may be defined as anoperation scheduled to depart a first airport at a specific time of day(and possibly a day of the week) and arrive at a second airport at asecond specific time of day. For example, an airline may operate hourlyflight segments between LaGuardia Airport in New York City and Reagannational Airport in Washington D.C. The flight segment leaving LaGuardiaat 7 AM each day is considered a first flight segment, a flight segmentleaving LaGuardia at 8 AM each day is considered a second flightsegment, etc. Often, an airline will use the same numerical indicator(e.g., Oceanic 1140 or Oceanic 3288) for the same flight segment on eachday. However, airlines sometimes treat weekend flight segmentsdifferently than weekday flight segments because airlines may flydifferent schedules on the weekends and/or air traffic congestion may bereduced. For example, a flight segment from LaGuardia to Reagan Nationalmay take one hour gate to gate during the week due to air traffic andthe like. However, the same flight segment may only take fifty minuteson the weekend.

Aspects described herein analyze historical data for different flightsegments to determine the likelihood of various flight operationvariances. These flight operation variances can be used to add buffersthat are flight segment specific. These flight segment specific bufferscan be more accurate than generally-applied buffers, meaning that such abuffer applied to a specific flight segment can be an accuraterepresentation of actual variations from scheduled operation. FIGS. 2Aand 2B illustrate exemplary data for a month that may be used to analyzeflight operation variances for a particular flight segment. FIG. 2Aillustrates a data table 200 for a particular flight segment that isscheduled to arrive at a destination airport at 11:50 AM (denoted as1150 in column 206 of the data table 200), wherein a first column 202indicates the thirty days in the particular month. A second column 204indicates the day of the week associated with each of the thirty days ofthe month. The third column 206 indicates the actual arrival time of theflight segment on each of the thirty days of the month. For example, onthe first day of the month, the flight segment arrived at 11:49 AM; oneminute early. On the second day of the month, the flight segment arrivedat 11:41 AM; nine minutes early. On the third day of the month, theflight segment arrived at 11:50 AM; on time. On the fourth day of themonth, the flight segment arrived at 11:58 AM; eight minutes late. Thefifth column 210 of the data table 200 provides a ranking of the ninemost-delayed operations of the flight segment over the course of themonth. For example, the flight segment on the twelfth day (in row 218)arrived at 12:25 PM, which is 35 minutes late. This flight segment wasthe most delayed over the course of the month and is therefore rankednumber one in the rank column 210. The flight segment on the eleventhday (in row 220) arrived at 12:20 PM, which is 30 minutes late. Thisflight segment was the second most-delayed flight segment over thecourse of the month and is therefore ranked number two in the rankcolumn 210. Similarly, the flight segment on the ninth day of the month(row 222) was the third-most delayed flight segment of the month, theflight segment on the nineteenth day of the month (row 224) was thefourth-most delayed flight segment of the month, the flight segment onthe fourth day of the month (row 226) was the fifth-most delayed flightsegment of the month, the flight segment on the twenty-fifth day of themonth (row 228) was the sixth-most delayed flight segment of the month,the flight segment on the twenty-third day of the month (row 230) wasthe seventh-most delayed flight segment of the month, the flight segmenton the eighth day of the month (row 232) was the eighth-most delayedflight segment of the month, and the flight segment on the twenty-secondday of the month (row 234) was the ninth-most delayed flight segment ofthe month. These flight segments are ranked three, four, five, six,seven, eight, and nine, respectively, in column 210.

With rankings determined, likelihoods of the flight segment arrivinglate (e.g., a predicted arrival time or predicted arrival time variance)can be determined. Using the exemplary thirty flight segments shown inFIG. 2A, a flight segment on a particular day represents approximately3% of the total flight segments. As discussed above, in this example,the worst flight segment of the month on the twelfth day (row 218)arrived 35 minutes late. Thus, 97% of the flight segments during themonth arrived no more than 34 minutes late. If an airline wants toestablish a buffer for the arrival time for this particular flightsegment that has a 97% reliability factor, then the airline couldestablish a buffer of 34 minutes. Alternatively, if the airline wants toestablish a buffer for the arrival time for this particular flightsegment that has a 97% reliability factor, then the airline couldestablish a buffer of 30 minutes (equal to the next longest flight) orany time between 30 minutes and 34 minutes. Continuing the example, thesecond worst flight segment of the month on the eleventh day (row 220)arrived 30 minutes late and the third worst flight segment of the monthon the ninth day (row 222) arrived 20 minutes late. The first, second,and third worst flight segments together represent approximately 10% ofthe total flight segments for the month. Thus, 90% of the flightsegments during the month arrived no more than 19 minutes late. If anairline wants to establish a buffer for the arrival time for thisparticular flight segment that has a 90% reliability factor, the airlinecould establish a buffer of 19 minutes. Continuing the example again,the fourth worst flight segment of the month on the nineteenth day (row224) arrived 18 minutes late, the fifth worst flight segment of themonth on the fourth day of the month (row 226) arrived eight minuteslate, and the sixth worst flight segment of the month on thetwenty-fifth day (row 228) arrived six minutes late. The first throughsixth worst flight segments together represent approximately 20% of thetotal flight segments for the month. Thus, 80% of the flight segmentsduring the month arrived no more than five minutes late. If an airlinewants to establish a buffer for the arrival time for this particularflight segment that has an 80% reliability factor, the airline couldestablish a buffer time of five minutes.

FIG. 2B illustrates a data table 250 for a particular flight segmentthat is scheduled to have a block time of two hours and thirty minutes(denoted as 2:30 in column 256 of the table 250), wherein a first column252 indicates the thirty days in a particular month. A second column 254indicates the day of the week associated with each of the thirty days ofthe month. The third column 256 indicates the actual block time of theflight segment on each of the thirty days of the month. For example, onthe first day of the month, the block time was two hours and twenty nineminutes; one minute short. On the second day of the month, the blocktime was two hours and twenty one minutes; nine minutes short. On thethird day of the month, the block time was two hours and thirty minutes;on time. On the fourth day of the month, the block time was two hoursand thirty eight minutes; eight minutes long. The fifth column 260 ofthe table 250 provides a ranking of the nine longest block times for theflight segment over the course of the month. For example, the block timefor the flight segment on the twelfth day (in row 268) was three hoursand five minutes, which is 35 minutes long (relative to the scheduledtwo hours and thirty minutes). This flight segment was the longest overthe course of the month and is therefore ranked number one in the rankcolumn 260. The block time for the flight segment on the eleventh day(in row 270) was three hours, which is thirty minutes long. This flightsegment was the second longest over the course of the month and istherefore ranked number two in the rank column 260. Similarly, the blocktime for the flight segment on the ninth day of the month (row 272) wasthe third longest of the month, the block time for the flight segment onthe nineteenth day of the month (row 274) was the fourth longest of themonth, the block time for the flight segment on the fourth day of themonth (row 276) was the fifth longest of the month, the block time forthe flight segment on the twenty-fifth day of the month (row 278) wasthe sixth longest of the month, the block time for the flight segment onthe twenty-third day of the month (row 280) was the seventh longest ofthe month, the block time for the flight segment on the eighth day ofthe month (row 282) was the eighth longest of the month, and the blocktime for the flight segment on the twenty-second day of the month (row284) was the ninth longest of the month. These flight segments areranked three, four, five, six, seven, eight, and nine, respectively, incolumn 260.

With rankings determined, likelihoods of the block time for the flightsegment being longer than scheduled (i.e., a predicted block timevariance) can be determined. Using the exemplary thirty flight segmentsshown in FIG. 2B, a flight segment on a particular day representsapproximately 3% of the total flight segments. As discussed above, inthis example, the block time for the worst flight segment of the monthon the twelfth day (row 268) was 35 minutes longer than scheduled. Thus,the block time for 97% of the flight segments during the month was nomore than 34 minutes long. If an airline wants to establish a buffer forthe block time for this particular flight segment that has a 97%reliability factor, then the airline could set a buffer of 34 minutes.Alternatively, if the airline wants to establish a buffer for the blocktime for this particular flight segment that has a 97% reliabilityfactor, then the airline could establish a buffer of 30 minutes (equalto the next longest flight) or any time between 30 minutes and 34minutes. Continuing the example, the block time for the second worstflight segment of the month on the eleventh day (row 220) was 30 minuteslonger than scheduled and the block time for the third worst flightsegment of the month on the ninth day (row 222) was 20 minutes longerthan scheduled. The first, second, and third worst flight segmentstogether represent approximately 10% of the total flight segments forthe month. Thus, the block time for 90% of the flight segments duringthe month was no more than 19 minutes longer than scheduled. If anairline wants to establish a buffer for the block time for thisparticular flight segment that has a 90% reliability factor, the airlinecould set a buffer of 19 minutes. Continuing the example again, theblock time for the fourth worst flight segment of the month on thenineteenth day (row 224) was 18 minutes longer than scheduled, the blocktime for the fifth worst flight segment of the month on the fourth dayof the month (row 226) was eight minutes longer than scheduled, and theblock time for the sixth worst flight segment of the month on thetwenty-fifth day (row 228) was six minutes longer than scheduled. Thefirst through sixth worst flight segments together representapproximately 20% of the total flight segments for the month. Thus, theblock time for 80% of the flight segments during the month was no morethan five minutes longer than scheduled. If an airline wants toestablish a buffer for the block time for this particular flight segmentthat has an 80% reliability factor, the airline could set a buffer timeof five minutes.

The tables in FIGS. 2A and 2B are provided for illustration purposes. Invarious instances, larger data sets could be used to provide more robustanalyses. For example, if the data set includes 100 flight segments,then a flight segment on a particular day represents 1% of the totalflight segments, and the airline may be able to select buffers with 99%reliability factors. As another example, if the data set includes 1000flight segments, then 10 flight segments represents 1% of the totalflight segments. Here, the airline could select buffers with 99.9%reliability factors. Additionally, larger data sets may reveal outlierinstances more readily. For example, referring again to FIG. 2A, theflight segments on the twelfth the day of the month (row 218) arrived 35minutes late. Based on the data shown in FIG. 2A, 3% of the flightsegments would be expected to arrive 35 minutes late. As describedabove, a buffer of thirty four minutes can be set with a 97% reliabilityfactor. However that data point on the twelfth day may be an outliersuch that if 1000 flight segments are looked at, only two or threeflight segments are 35 minutes late in such an instance, the 34 minutesbuffer would not represent a 97% reliability factor. Rather, the 34minute buffer would represent a greater than 99% reliability factor.

Additional likelihoods can be determined in a similar manner to arrivaltime and block time as explained above with reference to FIGS. 2A and2B.

The data in the data tables 200 and 250 in FIGS. 2A and 2B,respectively, can also be parsed and analyzed based on additionalfactors. For example, as discussed above, commercial flight segmentsgenerally do not experience the same delays on weekends that may beexperienced during weekdays because there are generally fewer flightsegments on weekends. Thus, the type of data shown in the data tables200 and 250 can be split into weekday flight segments and weekend flightsegments, and separate analyses can be performed on the different setsof data, for example. The type of data shown in the data tables 200 and250 could also be split by day of the week, and separate analyses can beperformed on the different sets of data.

In various aspects, the data or reliability factors can be representedby tags. For example, a tag may include a combination of a letter and anumber. The letter can represent a magnitude of a variance and thenumber can represent a likelihood of the variance for a particularflight segment. For example, for an arrival delay (a variance from thescheduled arrival time), the letter “A” may represent a delay of fiveminutes or less. The letter “B” may represent a delay of fifteen minutesor less. The letter “C” may represent a delay of thirty minutes or less.The letter “D” may represent a delay of an hour or less. The letter “E”may represent a delay of two hours or less. The letter “F” may representa delay of greater than two hours. Furthermore, the number “1” mayrepresent a 99% likelihood that the associated delay is not exceeded.The number “2” may represent a 97% likelihood that the associated delayis not exceeded. The number “3” may represent a 95% likelihood that theassociated delay is not exceeded. The number “4” may represent a 90%likelihood that the associated delay is not exceeded. The number “5” mayrepresent an 85% likelihood that the associated delay is not exceeded.The number “6” may represent an 80% likelihood that the associated delayis not exceeded. Thus, for example, a particular flight segment mayinclude the tag “B3,” which would mean that the flight segment isdelayed by fifteen minutes or less 95% of the time. Another flightsegment may include the tag “B4,” which would mean that the flightsegment is delayed by fifteen minutes or less 90% of the time. A flightsegment may include more than one tag. For example, a flight segment mayinclude a first tag “A6” and a second tag “B4,” meaning that the flightsegment is delayed five minutes or less 80% of the time and is delayedby fifteen minutes or less 90% of the time. The flight segment may haveother tags related to different operating variances, such as block timevariances.

Referring again to FIGS. 1A and 1B, when determining combinations offlight segments that can form an itinerary, aspects described herein canadd the determined buffers to the various flight segments in thecombination, based on an acceptable reliability factor. In variousinstances, the acceptable reliability factor may be the same for everyflight segment operated by a particular airline. As discussed in greaterdetail below, in various instances, different reliability factors may beapplied to different flight segments operated by an airline. Forexample, an airline may use a 99% reliability factor for high priorityflight segments (e.g., flight segments that are important to customers,flight segments that generate high revenues, flight segments that arestrategically important, and/or flight segments that return an aircraftto a maintenance facility), and buffers for the high priority flightsegment can be automatically set based on the analysis, described above,and the 99% reliability factor. As another example an airline may use a97% reliability factor for medium priority flight segments, and buffersfor the medium priority flight segment can be automatically set based onthe analysis, described above, and the 97% reliability factor. Asanother example, an airline may use a 95% reliability factor for lowpriority flight segments, and buffers for the low priority flightsegment can be automatically set based on the analysis, described above,and the 95% reliability factor. In the event that a combination offlight segments (with the determined buffers applied) would exceed apersonal duty time limit for a pilot, then the combination of flightsegments would be rejected (i.e., an itinerary would not be formed fromthat combination). For example, referring to FIG. 1B, if a possiblecombination of flight segments has a pilot flying four flight segments108 a, 108 b, 108 c, and 108 d, and the predicted block time for thecombination of flight segments (when the buffers for the flight segmentsare included) would exceed a pilot's total block time, then thecombination is not workable. As a result, the combination would not beassigned to an itinerary. Instead, the combination could be changed toinclude a different flight segment that has a shorter block time thanflight segment 108 d. Alternatively, the combination could be changed toinclude different earlier flight segments so that the combination caninclude flight segment 108 d.

FIG. 3 illustrates a process 300 that aspects described herein can useto assign combinations of flight segments to itineraries. In block 302of the process 300, historical operational data for the various flightsegments can be retrieved. For example, historical operational data,such as the type of data shown in FIGS. 2A and 2B, for flight segment108 d (in FIG. 1B) may be retrieved. In block 304 of the process 300, ananalysis on the retrieved data can be performed to determine thelikelihood's of various flight operation variances. For example, theanalysis may determine the likelihood that the flight segment 108 darrives five minutes late, the likelihood that the flight segment 108 darrives 10 minutes late, etc. As discussed, one or more tags can beapplied to the analysis for flight segment 108 d as a result of theanalysis. As another example, the analysis may determine the likelihoodthat the block time for the flight segment 108 d is five minutes longerthan scheduled, the likelihood that the block time for the flightsegment 108 d is 10 minutes longer than scheduled, etc. Again, one ormore tags can be applied to the analysis for flight segment 108 d. Inblock 306 of the process 300, an acceptable likelihood (i.e.,reliability factor) can be determined. As described above, in variousaspects, a single reliability factor can be applied to all operationvariances for all flight segments. In various other aspects, differentreliability factors can be applied to different flight segments and/orto different operation variances. For example, a first reliabilityfactors could be applied to an operation variances related to block timeand a second reliability factors could be applied to an operationvariances related to arrival time. In block 308, a combination of flightsegments (with buffers having reliability factors applied) that do notexceed personal limits of pilots (e.g., block time limits and total dutytime limits) is identified. In block 310, the identified combination offlight segments is assigned to an itinerary.

Other flight segments can be formed into other combinations of flightsegments and assigned to itineraries in a similar manner until all ofthe flight segments for an airline for a particular period (e.g., a day,a week, or a month) are assigned to itineraries. Pilots can then beassigned to the various itineraries. In various instances, itinerariesmay not be optimized at an individual level, but the schedule ofitineraries may be optimized. Put differently, an individual pilot'sitinerary may not be optimized (e.g., it may not utilize as much of hisblock time as possible), but the itineraries may provide an overalloptimized schedule for the airline's operations.

Aspects of systems and/or computer program products that perform theprocess 300 of FIG. 3 may provide a user interface that enables a user(e.g., a crew scheduler) to select the reliability factors for differentflight segments or groups of flight segments (e.g., high priority flightsegments, medium priority flight segments, and low priority flightsegments). The setting of buffers for the flight segments based on theanalysis and selected reliability factors may be invisible to the user.Put differently, the user may select a reliability factor for a flightsegment (or group of flight segments), and the system and/or computerprogram would update and output relevant times for the flight segment(e.g., block time and arrival time) based on the analysis of pastinstances of the flight segment and the selected reliability factor.

In various instances, any combination of flight segments can be assignedto any itinerary. Continuing the example above, a first possiblecombination of flight segments could be predicted to leave a pilot withtwo hours and fifty-five minutes of available block time by the time hewould fly flight segment 108 d. A second possible combination of flightsegments could be predicted to leave a pilot with three hours ofavailable block time by the time he would fly flight segment 108 d.Flight segment 108 d could be included in either the first possiblecombination or the second possible combination. However, the additionalavailable block time in the second combination of flight segmentsprovides an extra buffer compared to the first combination of flightsegments. For example, if an earlier flight segment in the first andsecond combinations has a block time of ten minutes longer than expected(even with a buffer applied), then the first combination only leaves thepilot with two hours and forty five minutes of block time available forflight segment 108 d—less than the two hours and forty-nine minutes withthe reliability factor described above. By contrast, the secondcombination of flight segments would have still leave the pilot with twohours and fifty minutes of available block time—still more than the twohours and forty-nine minutes. In such an exemplary instance, assigningflight segment 108 d to the second combination of flight segments can bea less-risky option than assigning flight segment 108 d to the firstcombination. For an airline that may operate hundreds or thousands offlight segments every day at different times and from differentairports, it is likely that some flight segments will have a riskiercrew scheduling than others. As described in greater detail below, if anairline can identify a certain subset of flight segments that areconsidered to be high priority, then the least risky crew assignmentscan be assigned to those flight segments. Similarly, the most risky crewassignments (e.g., crew assignments that are more at risk of causing aflight delay or cancellation due to the flight segment exceedingpersonal limits of the pilot(s)) can be assigned to low priority flightsegments.

FIG. 4 illustrates a timeline for an exemplary scenario 400 in whichfour flight segments 408, 410, 412, and 414 are arriving at HartsfieldInternational Airport in Atlanta 402 shortly before noon (represented bydashed line 404) and four flight segments 416, 418, 420, and 422 areleaving Atlanta 402 little after 1:00 PM (represented by dashed line406). For the purposes of illustration, in this scenario 400, thepossible combinations of flight segments for the flight crews for thefour incoming flight segments 408, 410, 412, and 414 include assignmentsto one of the four outgoing flight segments 416, 418, 420, and 422. Inthis scenario 400, the priorities of the four outgoing flight segments416, 418, 420, and 422 are not known. As a result, the crews from theinbound flight segments could be assigned to the outbound flightsegments based on a modified first in first out basis. The first pilotsinto Atlanta 402 are assigned to the first flight segment out ofAtlanta, except a few modifications are made based on flight segmentsthat are more likely to be substantially delayed. For example, flightsegment 408 is scheduled to arrive in Atlanta first at 11:50 AM.However, the flight segment 408 is historically late by 30 minutes ormore 5% of the time. The remaining flight segments 410, 412, and 414arrive later but are only 30 minutes late 1% or 2% of the time. Thus,even though flight segment 408 is scheduled to arrive first, forscheduling purposes its crew is treated as if they arrive last due tothe significantly more likely possibility that flight segment 408 willarrive at least 30 minutes late. Otherwise, the combination of flightsegments for the crew of flight segment 410, which is scheduled toarrive in Atlanta 402 at 11:53 AM, next includes flight segment 416 (asdenoted by dashed arrow 426), which departs Atlanta 402 at 1:00 PM.Similarly, the combination of flight segments for the crew of flightsegment 412, which is scheduled to arrive in Atlanta 402 at 11:55 AM,next includes flight segment 418 (as denoted by dashed arrow 428), whichdeparts Atlanta 402 at 1:01 PM. Also, the combination of flight segmentsfor the crew of flight segment 414, which is scheduled to arrive inAtlanta 402 at 11:55 AM, next includes flight segment 420 (as denoted bydashed arrow 430), which departs Atlanta 402 at 1:06 PM. Finally, thecombination of flight segments for the crew of flight segment 408, whichis scheduled to arrive in Atlanta 402 at 11:50 AM (but which has asignificantly higher likelihood of being late by 30 minutes or more),next includes flight segment 422 (as denoted by dashed arrow 424), whichdeparts Atlanta 402 at 1:10 PM.

The above-described assignment of flight crews to various aircraft inAtlanta 402 may result in a relatively even distribution of schedulerisk for the four departing flight segments 416, 418, 420, and 422.However, if one of the departing flight segments is of a higher prioritythan the others it may be advantageous to rearrange the crew assignmentsso that the highest priority flight segment has less scheduling risk.

FIG. 5A illustrates a table 500 with exemplary data that is used toassign priorities to different flight segments. A first column 502 ofthe table 500 identifies ten flight segment numbers. Although theseflight segment numbers are illustrated herein as the numbers 1 through10, the numbers could correspond to flight segment numbers used by anairline. Columns 504 and 506 of the table 500 identify the departureairport and arrival airport, respectively, for the flight segments.Columns 508 through 514 of the table 500 identify various differentexemplary priority rankings for the flight segments that can be used todetermine an overall priority ranking (in column 516). Column 508identifies a market value (e.g., revenue) for the flight segments.Column 510 identifies a financial ranking for the flight segments (on ascale of 1 to 5 where 1 is a high ranking and 5 is a low ranking). Invarious instances, the financial ranking may be correlated to orotherwise associated with the market value in column 510. For example,flight segment number two and flight segment number eight have a marketvalue (in column 508) of $110,000 and a corresponding financial rankingof 1. By contrast flight segment number four has a market value of$20,000 and a corresponding financial ranking of 5. In variousinstances, the financial rankings may not correlate or otherwisecorrespond to the market values. In such instances, the financialrankings may be entered or modified (e.g., by a system administrator) toreflect a “subjective” financial ranking to the airline. Column 512identifies a maintenance ranking for the flight segments (on a scale of1 to 5 where 1 is high ranking and 5 is low ranking). Airlines oftenmaintain maintenance facilities at certain airports that they fly to orfrom. The flight segments flying to those airports may be high priorityfor maintenance reasons (e.g., if an aircraft is due for maintenance,service, or an inspection). For example, flight segment 7 in the table500 is scheduled to arrive at Denver international Airport. In thisexemplary scenario, Denver may be a maintenance facility for thisparticular airline. Consequently, this flight segment may have amaintenance ranking of 1 (e.g., if the aircraft is due for scheduledmaintenance). The remaining nine flight segments do not arrive at Denverand therefore have a maintenance ranking of 5. Column 514 identifies astrategic ranking for the flight segments (on a scale of 1 to 5 where 1is high ranking and 5 is low ranking). A flight segment may be highpriority for reasons other than revenue or maintenance. For example, aparticular airline may be pursuing a marketing initiative in which theyadvertise hourly flight segments from LaGuardia Airport in New York Cityto Reagan National Airport in Washington, D.C. to attract businesstravelers. Some of the hourly flight segments may not be particularlyprofitable or may even lose money. However, those flight segments wouldbe important for the marketing efforts of the company. As anotherexample, a particular flight segment may fly between two hub airportsfor an airline. Such a flight segment may be strategically high prioritybecause the cancellation or delay of the flight segment could result ina cascade of subsequent missed connections or flight segments forpassengers. By contrast, a low revenue flight segment into a smallmarket may have low strategic priority. Additional rankings may beprovided on any number of factors that an airline finds to be important.In column 516 of the table 500, an overall ranking can be calculatedbased on the individual rankings. For example, in the table 500, thefinancial ranking (in column 510), the maintenance ranking (column 512),and the strategic ranking (column 514) are averaged together todetermine the overall ranking for the flight segments. Alternatively,the various rankings could be added together, averaged using a weightedaverage, or the like.

Referring now to FIG. 5B, different buffer reliability factors can beassigned to flight segments having different overall rankings (e.g.,from the table shown 500 shown in FIG. 5A). For example, FIG. 5Billustrates a table 530 of different reliability factors for buffers fordifferent overall rankings. The first column 532 of the table 530includes different ranges of overall rankings. For example, overallrankings between 1 and 2.5 can be considered high priority flightsegments, overall rankings between 2.6 and 3.5 can be considered mediumpriority flight segments, and overall rankings between 3.6 and 5 can beconsidered low priority flight segments. The ranges of overall rankingmay be associated with different reliability factors for buffersassociated with different operation variances. For example, column 534of the table 530 identifies allowable reliability factors for block timebuffers. For example, for high-priority flight segments, a block timebuffer must provide at least a 99% reliability factor. For mediumpriority flight segments a block time buffer must provide at least a 98%reliability factor. For low priority flight segments, a block timebuffer must provide at least a 97% reliability factor. As anotherexample, column 536 of the table 530 identifies allowable reliabilityfactors for duty time buffers (e.g., buffers designed to prevent a crewmember from exceeding total duty time limits). For example, forhigh-priority flight segments, a duty time buffer must provide at leasta 98% reliability factor. For medium priority flight segments, a dutytime buffer must provide at least a 97% reliability factor. For lowpriority flight segments, a duty time buffer must provide at least a 96%reliability factor. As another example, column 538 of the table 530identifies allowable reliability factors for rest time (e.g., the amountof time a pilot must be off-duty between on duty periods). For example,for high-priority flight segments, the rest time buffer must provide atleast a 99% reliability factor. For medium priority flight segments, arest time buffer must provide at least a 98% reliability factor. For lowpriority flight segments, the rest time buffer must provide at least a97% reliability factor. As another example, column 540 of the table 530identifies allowable reliability factors for connection risk (e.g., theamount of time it takes a pilot to transfer from one aircraft at anairport to a second aircraft at the airport). For example, forhigh-priority flight segments, the connection buffer must provide atleast a 97% reliability factor. For medium priority flight segments, aconnection buffer must provide at least a 96% reliability factor. Forlow priority flight segments, a connection buffer must provide at leasta 95% reliability factor. The exemplary reliability factors shown intable 530 are merely examples provided for illustration purposes. Anairline may determine reliability factors that suit its strategy.

Personnel may have personal limits related to operation priority. Forexample, continuing the examples above, pilots may be limited toperforming one high priority flight segment in a duty period.

FIG. 6 illustrates a scenario 600 that is similar to the scenario 400shown in FIG. 4, except that the combinations of flight segments forflight crews (from inbound flight segments to outbound flight segments)are based on a prioritization of the outbound flight segments. Flightsegment 608 is scheduled to arrive in Atlanta at 11:50 AM, but theflight segment 608 is historically late by thirty minutes or more 5% ofthe time. The remaining flight segments 610, 612, and 414 arrive laterbut are only thirty minutes late 1% or 2% of the time. Thus, even thoughflight segment 608 is scheduled to arrive first, for scheduling purposesits crew is treated as if they arrive last due to the higher likelihoodthat flight segment 608 will arrive at least thirty minutes late. Here,outbound flight segment 618 is determined to be a high-priority flightsegment. Flight segments 616 and 622 are determined to be mediumpriority flight segments, and flight segment 624 is determined to be alow priority flight segment. Referring again to FIG. 4, where prioritiesof the flight segments are not known or assigned, the combination offlight segments for the flight crew of inbound flight segment 610 nextincluded the first outbound flight segment 416. In the scenario 600shown in FIG. 6 however, flight segment 618 has been determined to be ofhigher priority than flight segment 616. Thus, the combination of flightsegments that includes inbound flight segment 610 also includes flightsegment 618 (as denoted by dashed arrow 630) even though flight segment618 is scheduled to depart after flight segment 616. Consequently, thecombination of flight segments that includes inbound flight segment 612also includes outbound flight segment 616 (as denoted by dashed arrow628). As before in the scenario 400 shown in FIG. 4, the combination offlight segments that includes inbound flight segment 614 also includesoutbound flight segment 622 (as denoted by dashed arrow 632), and thecombination of flight segments that includes inbound flight segment 608also includes outbound flight segment 624 (as denoted by dashed arrow626). With the arrangement of crew assignments shown in scenario 600,the scheduling risk for high-priority flight segment 618 has beendecreased relative to the crew assignments shown in scenario 400.

Additional buffers can also be considered when assigning crews todifferent flight segments. For example, if the crew of flight segment612 is likely to arrive in Atlanta with significantly more block timeavailable than the crew of flight segment 610, then the high-priorityflight segment 618 may be included in a combination of flight segmentsthat includes flight segment 612 (instead of flight segment 610). Asanother example, if the crew of flight segment 614 is likely to arrivein Atlanta with a longer period of time until the end of their dutyperiod than the crew of flight segment 610, then the high-priorityflight segment 618 may be included in a combination of flight segmentsthat includes flight segment 614 (instead of flight segment 610).

FIG. 7A illustrates a process 700 by which flight segments can beassigned to combinations of flight segments in a manner that the highestpriority flight segments are assigned to the least risky combination(s).In block 702, economic priorities for a plurality of flight segments canbe determined. As described above with reference to FIGS. 5A and 5B, theeconomic priorities for the flight segments can be based on objectivecriteria, subjective criteria, or a combination of objective andsubjective criteria. In block 704, possible combinations of flightsegments of the plurality of flight segments are identified. In block706, for the different possible combinations of flight segments, alikelihood that personal limits will be exceeded by the combination offlight segments can be determined. For example, a first combination offlight segments may have a 95% chance of not exceeding the personallimits of a pilot, based on past instances of the flight segments in thecombination, and a second combination may have a 99% chance of notexceeding the personal limits. In block 708, the highest priority flightsegment is identified and assigned to the combination of flight segmentswith the lowest risk of personal limits being exceeded by the flightsegments. As described above with reference to FIG. 5B, in variousinstances, the highest priority flight segment may be in a group offlight segments that are identified as being highest priority. Forexample, in FIG. 5B, a flight segment with an overall rank of 1 to 2.5is considered to be highest priority. Furthermore, the highest priorityflight segments may have different tolerable risk levels than mediumpriority or low priority flight segments. In such instances, thehigh-priority flight segments may be assigned to any one of a group ofpossible combinations of flight segments which have risk levels thatsatisfy the tolerable risk levels for a high-priority flight segment. Invarious other instances, flight segments may be ranked in a manner suchthat there is an identifiable highest priority flight segment amongstthe plurality of flight segments. In such an instance, the highestpriority flight segments may be assigned to the possible combination offlight segments which has the lowest risk level.

After the highest priority flight segment in block 710 has been assignedto a combination of flight segments, the process 700 can proceed toassign the remaining flight segments to combinations of flight segmentsin rank order based on priority of the flight segment. In block 710, theprocess 700 can identify the next highest priority flight segment fromamong the plurality of flight segments and assign this flight segment toa combination of flight segments that has the lowest risk of personallimits being exceeded by the flight segments. It is possible that thehighest priority flight segment and the next-highest priority flightsegment could be assigned to the same combination of flight segments orto different combinations of flight segments. In block 712, the process700 determines whether all flight segments have been assigned tocombinations of flight segments. If so, then in block 714, the process700 ends. If additional flight segments have not been assigned tocombinations of flight segments in block 712, then the process 700returns to block 710 and continues to assign flight segments tocombinations of flight segments by selecting the next highest priorityflight segment and assigning flight segment to the possible combinationof flight segments that is least likely to exceed personal limits.

In various instances, after the process 700 ends, the combinations offlight segments can be assigned to itineraries. Then, flight segmentcrews can be assigned to the itineraries.

In various aspects, it is possible that an airline may know the priorityof its flight segments but may not have the information to determine thelikelihood that a pilot's personal limits will be exceeded by aparticular flight segment (based on the pilot's flight segments leadingup to the particular flight segment). In such instances, pilots could beassigned to the flight segments based on available personal limits.Referring to FIG. 7B, a process 730 can begin in block 732 bydetermining the economic priorities for a plurality of flight segments.In block 734, candidate pilots to perform the plurality of flightsegments can be identified. In block 736, for the candidate pilotsremaining, personal limits can be determined (e.g., based on block time,duty time, rest time, or the like). In block 738, the pilots with likelythe most remaining personal limits can be assigned to the highestpriority flight segments. In various aspects, pilots could be sortedinto ranges of available personal time for flight scheduling purposesfor example, if a first pilot has two hours of remaining block time at asecond pilot has five hours of remaining block time, then it could beadvantageous to reserve the second pilot for longer flight segments(e.g., flight segments of three or four hours in length) and to use thefirst pilot for shorter flight segments (e.g., flight segments ofapproximately one hour). After pilots have been assigned to the highestpriority flight segment, then in block 740, pilots (from among theremaining pilots) with the next most remaining personal limits areassigned to the next highest priority flight segment. In block 742, theprocess 730 queries whether crews have been assigned to all flightsegments. If so, then in block 744 the process 730 ends. Returning toblock 742, if additional flight segments have not been assigned tocrews, then the process 730 returns to block 740.

The above-described aspects can be applicable to other groups ofoperators than pilots. For example, aspects can be used to scheduletrain operators, flight attendants, harbor pilots, etc. As anotherexample, aspects can be used to schedule surgeons for elective surgicalprocedures to ensure that surgeons do not become overly tired during aduty period.

The descriptions of the various aspects of the present invention havebeen presented for purposes of illustration, but are not intended to beexhaustive or limited to the aspects disclosed. Many modifications andvariations will be apparent to those of ordinary skill in the artwithout departing from the scope and spirit of the described aspects.The terminology used herein was chosen to best explain the principles ofthe aspects, the practical application or technical improvement overtechnologies found in the marketplace, or to enable others of ordinaryskill in the art to understand the aspects disclosed herein.

In the preceding paragraphs, reference is made to aspects presented inthis disclosure. However, the scope of the present disclosure is notlimited to specific described aspects. Instead, any combination of thepreceding features and elements, whether related to different aspects ornot, is contemplated to implement and practice contemplated aspects.Furthermore, although aspects disclosed herein may achieve advantagesover other possible solutions or over the prior art, whether or not aparticular advantage is achieved by a given aspect is not limiting ofthe scope of the present disclosure. Thus, the preceding aspects,features, and advantages are merely illustrative and are not consideredelements or limitations of the appended claims except where explicitlyrecited in a claim(s). Likewise, reference to “the invention” shall notbe construed as a generalization of any inventive subject matterdisclosed herein and shall not be considered to be an element orlimitation of the appended claims except where explicitly recited in aclaim(s).

Aspects may take the form of an entirely hardware aspect, an entirelysoftware aspect (including firmware, resident software, micro-code,etc.) or an aspect combining software and hardware aspects that may allgenerally be referred to herein as a “circuit,” “module” or “system.”

Aspects may be a system, a method, and/or a computer program product.The computer program product may include a computer readable storagemedium (or media) having computer readable program instructions thereonfor causing a processor to carry out aspects of the present invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Smalltalk, C++ or the like, andconventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some aspects, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects are described herein with reference to flowchart illustrationsand/or block diagrams of methods, apparatus (systems), and computerprogram products according to aspects of the invention. It will beunderstood that each block of the flowchart illustrations and/or blockdiagrams, and combinations of blocks in the flowchart illustrationsand/or block diagrams, can be implemented by computer readable programinstructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousaspects of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the Figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

Aspects may be provided to end users through a cloud computinginfrastructure. Cloud computing generally refers to the provision ofscalable computing resources as a service over a network. More formally,cloud computing may be defined as a computing capability that providesan abstraction between the computing resource and its underlyingtechnical architecture (e.g., servers, storage, networks), enablingconvenient, on-demand network access to a shared pool of configurablecomputing resources that can be rapidly provisioned and released withminimal management effort or service provider interaction. Thus, cloudcomputing allows a user to access virtual computing resources (e.g.,storage, data, applications, and even complete virtualized computingsystems) in “the cloud,” without regard for the underlying physicalsystems (or locations of those systems) used to provide the computingresources.

Typically, cloud computing resources are provided to a user on apay-per-use basis, where users are charged only for the computingresources actually used (e.g. an amount of storage space consumed by auser or a number of virtualized systems instantiated by the user). Auser can access any of the resources that reside in the cloud at anytime, and from anywhere across the Internet. In context of the presentinvention, a user may access applications (e.g., a crew schedulingapplication) or related data available in the cloud. For example, thecrew scheduling application could execute on a computing system in thecloud and analyze historical flight segment data to identify timevariances. In such a case, the analysis of historical data could operateon historical flight segment information stored at a storage location inthe cloud. A resulting crew schedule could also be stored at a storagelocation in the cloud. Doing so allows a user to access this informationfrom any computing system attached to a network connected to the cloud(e.g., the Internet).

While the foregoing is directed to aspects, other and further aspectsmay be devised without departing from the basic scope thereof, and thescope thereof is determined by the claims that follow.

What is claimed is:
 1. A method for assigning various operations to anitinerary, the method comprising: selecting a reliability factor;determining at least one predicted time variance for the variousoperations based on past instances of the various operations and theselected reliability factor; identifying a possible combination ofoperations, including the respective at least one predicted timevariance, that does not exceed at least one personal limit of personnel;and assigning the identified possible combination of operations to anitinerary.
 2. The method of claim 1, wherein the various operations is aflight segment of a commercial aircraft, wherein the possiblecombination of operations is a combination of flight segments, whereinthe personnel are pilots, wherein the at least one predicted timevariance comprises a predicted block time variance for the combinationof flight segments, and wherein the at least one personal limitcomprises an available block time.
 3. The method of claim 1, wherein thevarious operations is a flight segment of a commercial aircraft, whereinthe possible combination of operations is a combination of flightsegments, wherein the personnel are pilots, wherein the at least onepredicted time variance comprises a predicted arrival time variance fora last flight segment in the combination of flight segments, and whereinthe at least one personal limit comprises a predicted remaining dutytime.
 4. The method of claim 1, wherein the various operations is aflight segment of a commercial aircraft, wherein the possiblecombination of operations is a combination of flight segments, whereinthe personnel are pilots, wherein the at least one predicted timevariance comprises a connection time between flight segments of thecombination of flight segments, and wherein the at least one personallimit comprises a minimum required connection time.
 5. The method ofclaim 1, wherein the various operations is a flight segment of acommercial aircraft, wherein the possible combination of operations is acombination of flight segments, wherein the personnel are pilots,wherein the at least one predicted time variance comprises a predictedarrival time for a last flight segment of the combination of flightsegments, wherein the at least one personal limit comprises a predictedstart-of-rest time, and wherein a predicted start-of-rest time for apilot satisfies the at least one predicted time variance if thepredicted start-of-rest time is later than the predicted arrival time.6. The method of claim 1, wherein the various operations are assignedpriority values, and wherein the operations are assigned to itinerariesbased on the priority values.
 7. The method of claim 6, whereinidentifying a possible combination of operations comprises identifying aplurality of possible combinations of operations; and furthercomprising: calculating, for the plurality of operations, a risk levelthat a combination of operations will exceed the at least one personallimit of the personnel; and assigning to an itinerary a combination ofoperations from the plurality of operations that has a low risk leveland that includes a high priority operation.
 8. A system, comprising:memory storing past instances of various operations; and a processorconfigured to: receive a selection of a reliability factor; and analyzeto determining at least one predicted time variance for the variousoperations based on past instances of each of the various operations andthe reliability factor; identify a possible combination of operations,including the respective at least one predicted time variance, that doesnot exceed at least one personal limit of personnel; and assign theidentified possible combination of operations to an itinerary.
 9. Thesystem of claim 8, wherein the various operations is a flight segment ofa commercial aircraft, wherein the possible combination of operations isa combination of flight segments, wherein the personnel are pilots,wherein the at least one predicted time variance comprises a predictedblock time variance for the combination of flight segments, and whereinthe at least one personal limit comprises an available block time. 10.The system of claim 8, wherein the various operations is a flightsegment of a commercial aircraft, wherein the possible combination ofoperations is a combination of flight segments, wherein the personnelare pilots, wherein the at least one predicted time variance comprises apredicted arrival time variance for a last flight segment in thecombination of flight segments, and wherein the at least one personallimit comprises a predicted remaining duty time.
 11. The system of claim8, wherein the various operations is a flight segment of a commercialaircraft, wherein the possible combination of operations is acombination of flight segments, wherein the personnel are pilots,wherein the at least one predicted time variance comprises a connectiontime between flight segments of the combination of flight segments,wherein the at least one personal limit comprises a minimum connectiontime.
 12. The system of claim 8, wherein the various operations is aflight segment of a commercial aircraft, wherein the possiblecombination of operations is a combination of flight segments, whereinthe personnel are pilots, wherein the at least one predicted timevariance comprises a predicted arrival time for a last flight segment ofthe combination of flight segments, wherein the at least one personallimit comprises a predicted start-of-rest time, and wherein a predictedstart-of-rest time for a pilot satisfies the at least one predicted timevariance if the predicted start-of-rest time is later than the predictedarrival time.
 13. The system of claim 8, wherein the various operationsare assigned priority values, and wherein the operations are assigned toitineraries based on the priority values.
 14. The system of claim 13,wherein the processor is further configured to: identify a plurality ofpossible combination of operations; calculate, for the plurality ofcombinations of operations, a risk level that a combination ofoperations will exceed the at least one personal limit of the personnel;and assign to an itinerary a combination of operations from theplurality of operations that has a low risk level and that includes ahigh priority operation.
 15. A computer program product for assigningpersonnel to various operations, the computer program productcomprising: a computer-readable storage medium having computer-readableprogram code embodied therewith, the computer-readable program codeexecutable by one or more computer processors to: receive a selection ofa reliability factor; and determine at least one predicted time variancefor the various operations based on past instances of the variousoperations and the reliability factor; identify a possible combinationof operations, including the respective at least one predicted timevariance, that does not exceed at least one personal limit of personnel;and assign the identified combination of operations to an itinerary. 16.The computer program product of claim 15, wherein the various operationsis a flight segment of a commercial aircraft, wherein the possiblecombination of operations is a combination of flight segments, whereinthe personnel are pilots, wherein the at least one predicted timevariance comprises a predicted block time variance for the combinationof flight segments, and wherein the at least one personal limitcomprises an available block time.
 17. The computer program product ofclaim 15, wherein the various operations is a flight segment of acommercial aircraft, wherein the possible combination of operations is acombination of flight segments, wherein the personnel are pilots,wherein the at least one predicted time variance comprises a predictedarrival time variance for a last flight segment in the combination offlight segments, and wherein the at least one personal limit comprises apredicted remaining duty time.
 18. The computer program product of claim15, wherein the various operations is a flight segment of a commercialaircraft, wherein the possible combination of operations is acombination of flight segments, wherein the personnel are pilots,wherein the at least one predicted time variance comprises a connectiontime between flight segments of the combination of flight segments,wherein the at least one personal limit comprises a minimum connectiontime.
 19. The computer program product of claim 15, wherein the variousoperations is a flight segment of a commercial aircraft, wherein thepossible combination of operations is a combination of flight segments,wherein the personnel are pilots, wherein the at least one predictedtime variance comprises a predicted arrival time for a last flightsegment of the combination of flight segments, wherein the at least onepersonal limit comprises a predicted start-of-rest time, and wherein apredicted start-of-rest time for a pilot satisfies the at least onepredicted time variance if the predicted start-of-rest time is laterthan the predicted arrival time.
 20. The computer program product ofclaim 15, wherein the various operations are assigned priority values,and wherein the operations are assigned to itineraries based on thepriority values.
 21. The computer program product of claim 20, whereinthe computer-readable program code is further executable to: identify aplurality of possible combination of operations; calculate, for theplurality of combinations of operations, a risk level that a combinationof operations will exceed the at least one personal limit of thepersonnel; and assign to an itinerary a combination of operations fromthe plurality of operations that has a low risk level and that includesa high priority operation.